1. Field
One or more embodiments relate to methods and devices for controlling display of a display device.
2. Description of the Related Art
Among hormones secreted from the human body, melatonin serves as a biological clock. When night comes, melatonin is secreted all over the body and informs each part of the body that night has come. When melatonin is secreted, sleeping is induced.
When morning comes and light illuminates, secretion of melatonin is suppressed and a human wakes up from sleeping. A wavelength around 464 nm in particular suppresses secretion of melatonin in humans. Generally, since people recognize light having a central wavelength around 470 nm as blue light, light having a wavelength around 464 nm is considered to be blue light.